The decision to equip or not equip with ADS-B out equipment will depend on certain features of your airplane and will mostly be dependent upon what types of airspace you fly in.  While the decision to equip or not equip is based on these factors, it is undeniable that reporting your plane and position via ADS-B increases the safety of the National Airspace System for all who use it!

The FAA has put together this very helpful flow chart which will help you make your decision.